Hereinafter, an idle mode of a mobile station and a paging group related to the exemplary embodiments of the present invention will be briefly described.
Generally, when a mobile station moves in a wireless link environment, which is configured of multiple base stations, the idle mode refers to an operation mode of a mobile station that can enable the mobile station to periodically perform DL (Down Link) broadcast traffic transmission (or transport) even if the corresponding mobile station is not registered to a specific base station.
In case the mobile station does not receive any traffic from the base station for a predetermined period of time, the operation mode of the mobile station may be shifted to the idle mode for the purpose of Power saving. The mobile station being shifted to the idle mode may receive a broadcast message (e.g., paging message) being transmitted from the base station during an average interval (Available interval), so as to determine whether the mobile station should shift its operation mode to a normal mode or remain operating in the idle mode. Additionally, by performing a position (or location) update, the mobile station operating in the idle mode may notify its position (or location) to a Paging controller.
By removing handover-related activation requests and general management requests, the idle mode may provide the mobile station with benefits. By limiting the mobile station activities to performing scanning in a discrete cycle period, the idle mode may allow the mobile station to save the power and management resources used by the mobile station.
Furthermore, by providing provides a simple and adequate method for notifying the mobile station of any pending downlink traffic, and by removing any wireless (or radio) interface and network HO (Hand Over) traffic from a non-active (or inactive) mobile station, the idle mode may provide the network and base station with benefits.
Herein, paging refers to a function of determining the position (or location) (e.g., which base station or which switch (or exchange) center) of a corresponding MS (Mobile Station), when an incoming call occurs in a mobile communication. Multiple BSs (Base Stations) supporting the Idle Mode may belong to a specific Paging Group, so as to configure a paging region (or area or section).
At this point, a paging group represents a logical group. When a traffic targeting a mobile station (MS) exists, the purpose of the paging group is to provide a close-range area (or region or section) that can be paged via DL (Down Link). It is preferable that the paging group satisfies the conditions of being large enough to allow a specific mobile station to exist within the same paging group during most of the time and being small enough to maintaining an adequate level of paging load (or duty).
However, in a general IEEE802.16 based wireless communication system, the mobile station is forced to enter the idle mode, even if the mobile station is not required to perform any paging procedure in order to save power. And, accordingly, the mobile station is unnecessarily forced to be allocated with information related to paging. In this case, while being operated in the idle mode, the mobile station is forced to be activated (or awake) during the corresponding paging section (or paging interval) even if the mobile station is not required to receive any paging message.
Therefore, the base station triggers a context retention timer. Meanwhile, the base station stores the connection information (context) of the mobile station. Thus, in order to facilitate the network re-entry of the mobile station, a DCR (Deregistration with Content Retention) mode is defined.
The DCR mode may be initiated through a message requesting the base station for a DCR mode entry, i.e., a deregistration request (DREG-REQ) message. However, in case the mobile station is required to be deregistered due to the circumstances of the base station (e.g., base station reconfiguration or restart, etc.), and when the base station directs the corresponding mobile station with DCR mode entry, the network re-entry procedure of the deregistered mobile station may be efficiently performed.
However, in the current IEEE 802.16m system, the method of the base station for initiating the DCR mode is not yet defined. And, therefore, an efficient procedure for initiating the DCR mode is required to be defined.
Subsequently, an AAI_SON-ADV (Self Organizing and Optimizing Network) message will hereinafter be described.
The AAI_SON-ADV (Self Organizing and Optimizing Network) message is used for broadcasting SON-related information from a base station (ABS), which is connected to (or accessing) a core access network supporting the self organizing and optimizing network (SON).
An Action Type field is defined in the AAI_SON-ADV message as shown in Table 1 shown below.
TABLE 1SizeField(bits)Value/DescriptionConditionAction3Used to indicate the purpose of thismandatoryTypemessage0b000: ABS Reconfiguration0b001: ABS Restart0b010: ABS Scanning0b011: ABS Reliability0b100: LDM parameter change
Referring to Table 1, the Action Type field may indicate (or direct) ABS reconfiguration, ABS Restart, ABS scanning, ABS Reliability, and LDM (Low Duty Mode) parameter change.
Depending upon the action type, the AAI_SON-ADV message may be accompanied by subordinate fields. And, by using such subordinate fields, a service unavailable point, at which the base station is unable to provide normal services to the mobile station, a service unavailable section (or interval), and/or a new frequency band (FA).
However, in the current IEEE 802.16m system, in case the base station broadcasts the AAI_SON-ADV message, a detailed action (or operation) procedure, e.g., whether or not the DCR mode is being initiated, of the mobile station receiving the AAI_SON-ADV message transmitted from the base station is yet to be defined, an efficient procedure for performing the same is required to be defined.